I played a lot of JK1 on the MSN gaming zone back in the day, was great fun.
But to be honest JK2 is probably the better game, the lightsabre fights are so much more fun, in JK1 having a lightsabre fight online was kind of like jousting, you had two lightsabre moves, one was way better then the other, sweeping it in a huge arc, so you charged at each other, and had to time the swing at the right time to get your opponent, quite bizarre.
For some reason I didn't find JK3 as much fun, the way the game played was slightly different but I couldnt put my finger on it.